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P 1, 1964 G. H. WOTRING 3,147,401

ELECTRIC IGNITION DEVICE Filed July 20, 196i 3 Sheets-Sheet l Attorney.

p 1, 1964 G. H. WOTRlNG 3,147,401

ELECTRIC IGNITION DEVICE 3 Sheets-Sheet 2 Filed July 20, 1961 Ina/enter.- Gay/andh. n a'r/ifg,

Sept. 1, 1964 H. WOTRING 3,

ELECTRIC IGNITION DEVICE Filed July 20, 1961 3 Sheets-Sheet 5 AJZ'ornay.

United States Patent 3,147, 11 ELECTRIC IGNITION DEVICE Gaylord H. Wotring, Morrison, 111., assignor to General Electric Company, a corporation of New York Filed an 20, 1961, Ser. No. 125,557 9 Claims. (Cl. 317-97) This invention relates to an improved electric igniter, and particularly to an electric igniter operable to ignite a burner carrying combustible fluid.

An important object of this invention is to provide an improved electric igniter which is novel in structure and eflicient in operation.

An additional object of my invention is to provide an improved electric igniter which achieves positive ignition of a combustible gaseous substance at a frequency which enhances the longevity of the device, and also operates in a relatively quiet fashion.

Another object of this invention is to provide an improved electric igniter which may be effectively operated by an alternating current power supply to achieve an efficient ignition of a combustible substance located in proximity to the igniter by rotatable oscillating movement of an electrode.

A further object of this invention is to provide an improved electric igniter which is simplified in construction, readily manufacturable, and of durable construction.

In carrying out my invention, in one form thereof, I apply it to an electric gas ignition device. This device includes a stationary field structure including a winding which is connected in series with a pair of relatively movable electrodes. A rotor is arranged for excitation by this field structure. One of the electrodes is fastened coaxially to the rotor and spring biased into normally closed engagement with the stationary electrode. When the field structure is excited by the winding, the spring biased movable electrode is separated from the stationary electrode by rotation of the rotor against the force of the spring. This produces an ignition arc. Since the winding is in series with the electrodes, it is deenergized when the electrodes are separated, and the spring then returns the movable electrode to its closed position after a rotation thereof of approximately 60. As long as the winding and electrodes are energized, the movable electrode will continue to oscillate between its open and closed positions providing an arc for fuel ignition. Such an arrangement of electrodes and field provides eflicient and positive ignition of a combustible gaseous substance at a frequency which enhances the longevity of the device, and also achieves relatively quiet operation.

Further aspects of my invention will become apparent hereinafter, and the specification concludes with claims particularly pointing out and distinctly claiming the subject matter which I regard as my invention. The invention, however, as to organization and method of operation, together with other objects and advantages thereof, may best be understood by reference to the following description when taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front elevation view of a burner mounted master control embodying my improved electric igniter in one form thereof;

FIG. 2 is a right end view of the master control of FIG. 1, showing the front of the electric igniter;

FIG. 3 is a bottom view of the master control of FIG. 1, showing the electric igniter mounted thereon;

FIG. 4 is a left end view of the master control of FIG. 1, showing the rear of the electric igniter;

3,147,401 Patented Sept. 1, 1964 ice FIG. 5 is an enlarged sectional view of the electric igniter, showing the various interior parts thereof;

FIG. 6 is an enlarged frontal view of the electric igniter;

FIG. 7 is an enlarged rear view of the electric igniter;

FIG. 8 is a circuit diagram for the electric igniter; and

FIG. 9 is an exploded perspective view of the electric igniter.

Referring in detail to the drawings, and in particular to FIGS. 14, there is shown a master control 1 for a gas burner wherein my invention has been advantageously employed. Certain features of this control, other than the electric igniter claimed herein, are the invention of Stanley J. Budlane, and are described in detail and claimed in the copending application of said Budlane, Serial No. 125,458, filed concurrently herewith and assigned to the same assignee as the present invention. Control 1 has an elongated over-all appearance and essentially includes flame detector tube 3, which senses the presence of a flame, baflle 5 which controls the flow of secondary air to a flame sensed by the detector tube 3, control box 7 which supports and contains the actuating end of the flame detector as well as various other controlling elements of control 1, and electrical igniter 9. The flame detector tube 3 has a rod (not shown) attached to the inner walls of its outer end, and it is the type of detector wherein one side of the tube is placed near the burner flame so that the tube warps to actuate associated contacts by movement of the interior rod. Baflie 5 is specially configured and located relative to the flame detector tube 3 and gas burner 6 to expeditiously control the flow of secondary air to the flame which is being detected. The control box 7 is attached to baffle 5 by means of screws 11 (FIG. 3) and serves as an over-all housing for a relay, a lockout heater and various other circuit controlling elements such as the relay contacts, the lockout contacts and the flame detector contacts (which are not shown).

To efficiently ignite a combustible substance, such as gas emanating from burner 6, in a novel and improved manner, as shown in detail in FIG. 5, the electric igniter 9 has been provided. Igniter 9 basically includes stationary and movable electrodes 13 and 15, respectively, which are operated by an electrically controlled rotor 17. More particularly, as shown in FIGS. 5 and 9, the various parts of igniter 9 are supported within an open ended tubular metallic casing 19. Casing 19 serves as a protective housing for most of the movable igniter parts and also forms part of a magnetic circuit which excites rotor 17 The rear 21 of casing 19 includes a plurality of tabs 23 (FIGS. 4 and 7). Tabs 23 are extended through peripheral slots 24 of an insulating cap member 25 and then bent over upon it to close one end of the casing 19. Cap member 25 has a pair of parallel slots 27 formed therein for receiving terminal legs 29 of a U-shaped terminal 31. (See FIG. 5.) Terminal 31 also includes a bight 33 which is disposed on the inside wall of cap member 25, as shown in FIG. 5. On the side of bight 33 closest to the inner wall of cap member 25, the flat supporting section 35 (FIG. 9) of a generally V-shaped resilient contact 37 is welded to terminal 31. Resilient portion 39 of contact 37 extends angularly inwardly and away from curved bend 40 of the spring to normally engage and axially bias the innermost or rearward end 41 of movable electrode 15.

The movable electrode 15 includes an elongated cylindrically configured rod 43 having a knurled section 45 near its rearward end 41 and a cutout step 47 at its outer and front end 49. (See FIG. 5.) The knurled section 45 of rod 43 is pressed into engagement with an aperture of an insulating hub 51, which serves to mount the rotor 17. Hub 51 has an annular flange 53 which is fitted into engagement with an annular shoulder 55 in the in terior of metal sleeve 57. The outermost end of the sleeve 57 is staked to flange 53 of the hub after hub 51 has been positioned on the sleeve 57 by coining over tabs 59. For mounting the rotor 17 upon the movable electrode 15, an annular shoulder 61 is formed in the exterior surface of sleeve 57. After rotor 17 has been fitted into engagement with shoulder 61 of sleeve 57, it is staked thereto by the coined over tabs 59. The rotor 17 is thus attached to movable electrode 15 by means of hub 51 and sleeve 57.

As shown in FIG. 9, the rotor 17 is laminated and provides a pair of diametrically opposed salient poles 17a and 17b. To intermittently excite rotor 17 and thereby rotate the movable electrode 15, an electromagnetic field is established by a coil or winding 63 and an associated core assembly 65 (FIG. 9). More particularly, coil 63 includes a multitude of turns of wire wound upon insulating bobbin 67. The bobbin 67 comprises cylindrical section 69 and annular shoulders 71 and 73 formed at the opposite ends thereof. Shoulder 71 has a relatively flat outer surface which faces rotor 17. Shoulder 73 of the bobbin 67 has a specially shaped recess 75 (FIG. 9) formed in its outer surface to compactly and cooperatively receive stacked laminations 77 of the core assembly 65.

Turning now to a discussion of core assembly 65, attention is further directed to FIGS. and 9. Core assembly 65 includes metallic sleeve 79 which has a plurality of conductive laminations 77 staked thereto by coining over tabs 81 of the sleeve. Each of the ends 33 and 85 of sleeve 79 has a bearing 87 of an insulating material, such at Teflon, positioned therein. Bearings 87 have coaxially disposed apertures 89 through which rod 43 of the movable electrode is extended, and they serve as hearing bushings for rotatably supporting the movable electrode 15, as well as rotor 17, which is attached thereto.

The coil and bobbin assembly, with core assembly 65 inserted therein, is positioned within tubular casing 19, as shown in FIG. 5, with the outermost lamination 77 of the stationary electromagnetic structure facing the front end 91 of casing 19. The opposed arcuate edges 92 of core laminations 77 are contiguous to inner cylindrical surfaces of casing 19 near its front end 91 and provide a flux path into the metallic casing 19. The rear end 21 of casing 19 is bifurcated to provide a pair of diametrically opposed and cylindrical salient pole faces 94 (FIG. 9). The salient pole faces 94 of the stationary field structure are normally misaligned with the salient poles 17a and 17b of rotor 1'7. When coil 63 is energized, a flux path is established through sleeve 79, laminations 77 and casing 19 to the salient pole faces 94, and then back to the core sleeve 79 through rotor 17. It will be understood that when alternating current is pulsed to the coil 63, the direction of the flux path changes for every half cycle. To establish this flux path, upon energization of coil 63, the rotor poles 17a and 1711 line up with the stationary poles 94 of casing 19 to effect limited rotation of the movable electrode 15.

To cover the slots formed in casing 19 between the salient pole faces 94, and thereby protect and insulate the rotor end of casing 19, as shown in FIGS. 5 and 9, insulating sleeve 19a has been provided. Sleeve 19a is fitted around the casing near and at end 21 to cover the slots and salient poles 94.

To close the open front end 91 of the casing 19, as well as to support fixed electrode 13 and a coil terminal 93, and also insulate both of the electrodes 13 and 15 from each other, I have provided head 95. Head 95 is made of a suitable insulating material which withstands the particular temperature environment involved and includes a pair of diametrically opposed segments 97 which extend rearwardly from a disc-shaped platform 99. Segments 97 have cylindrical outer surfaces which fit snugly into tubular casing 19 near front end 91 thereof, and rear walls 101 which are flattened and parallel to platform 99 for secure engagement with two contiguous faces of the front field lamination 77. (See FIGS. 5 and 9.) For securely holding insulating head within casing 19, tabs 102 at the front end 91 over against platform 99 of the head, as shown in FIG. 6.

To support fixed electrode 13 and guide the rotative movement of movable electrode 15, head 95 includes a knob-like projection 103 (FIG. 9) which extends outwardly in upright fashion from platform 99. Projection 193 is oval in cross section, with two spaced bores 105 and 107 formed therein. The axes of bores 105 and 107 are in parallel relationship and perpendicular to platform 99. Bore 105 is located on one side of projection 193 (viewing FIG. 6) near the periphery of the discshaped platform 99 and opens outwardly through the front and rear ends of head 95 (FIG. 5) so that fixed electrode 13 may be positioned within and secured to the bore 105 by staking. Bore 197 is located on the other side of projection 103 (viewing FIG. 6) and is in axial alignment with apertures 89 of the bearings 87, opening outwardly through the front and rear ends of head 95 (FIG. 5) so that movable electrode 15 may be extended therethrough and guided thereby. Bore 107 also includes counterbore 109 at its outer mouth, the purpose of which shall become apparent hereinafter.

As shown in FIG. 5, the stationary electrode 13 includes a rod-like portion with a terminal section formed at its inner end. Cutout step 47 is formed at outer end 119 of electrode 13, in the same manner as for movable electrode 15.

To provide an efiicient and improved contact action for the fixed and movable electrodes 13 and 15, as shown in FIGS. 5 and 6, the specially configured contact support sections 111 and 113 have been provided. Sections 111 and 113 are each formed from a flat strip of conductive metal which is bent over transversely at 115 and 117 to form a pair of offset parallel portions 119 and 121 connected by an intermediate portion 122 disposed angularly to each of the portions 119 and 121 (FIG. 5). Portion 119 of each contact support section has an angled edge 123 (FIG. 9) formed at its outer end. To mount the contact support sections 111 and 113 upon the front ends of the electrodes, the angled edge 123 of each of the contact sections is placed against shoulder 47a (FIG. 5) of the cutout step 47, and portion 119 is thereupon welded to the electrode shaft, as shown by reference 7 numeral 125 in FIG. 9.

The contact sections 111 and 113 are similarly configured and constructed so that when they are mounted on the electrode shafts, the outer portion 121 of the movable electrode 15 may rotate into spaced parallel juxtaposition with the outer portion 121 of stationary electrode 13. (See FIG. 6.) Contact buttons 127 are attached to the outer end surfaces of outer contact portions 121 and they are preferably of tungsten metal. The contact button 127 of the movable electrode 15 is thus mounted upon rod 43 so that it may rotate into contact kissing engagement with the contact button 127 of stationary electrode 13.

To control the movement of electrode 15 and impart an oscillatory rotative motion thereto, as shown in FIGS. 5 and 9, I have provided a double diameter helical spring 129. The spring 129 surrounds rod 43 of movable electrode 15 and includes a section 131 of larger diameter which fits partially into counterbore 109 of bore 107 of head 95. The free end of section 131 of the spring (FIG. 6) is hooked or looped at 133 for insertion into a triangular-shaped recess 135 of head 95. In particular, an apex of recess 135 communicates transversely with counterbore 109 for receiving hooked end 133 of the spring 129. Recess 135 thus serves to fixedly support spring end 133 in head 95. Spring 129 also includes section 137 of smaller diameter than spring section 131.

of the casing are turned The free end of spring section 137 is welded to rod 43 of the movable electrode so that the spring 129 normally biases the contact button 127 of movable electrode 15 into rotative engagement with the contact button 127 of stationary electrode 13. The biasing force imparted to movable electrode 15 is such as to assure positive electrical contact wiping but also allows the electrode contacts to be readily driven open upon energization of coil 63.

For attaching my improved igniter 9 to the master control 1, as shown in FIGS. 5 and 9, a bracket 130 has been utilized. Arcuate plate section 130a of bracket 130 is welded to the outer surface of casing 19 of the igniter, and an L-shaped flange section 13% of bracket 130 is fastened to side 132 of control box 7 by screws 1300 (FIG. 4).

For an explanation of the operation of my improved electric igniter 9, attention is now directed to FIGS. 5 and 8. FIG. 8 is a schematic circuit diagram wherein the electrodes 13 and 15 are connected in series with reley coil 63 and a suitable external control switch 145, across a source of alternating current (not shown). More particularly, as shown in FIG. 8, one end 139 of coil 63 is connected to coil terminal 93. (See also FIG. 5.) Terminal 93 is connected to the alternating current source on one side of the line at terminal 140. The other end 141 of coil 63 is connected to terminal 143 of stationary electrode 13. Terminal 31 spring biases movable electrode 15 axially and outwardly from casing 19, and also connects the movable electrode 15 to the other side of the line at terminal 146 through the external control switch 145.

Upon energization of the ignition circuit by closing the contacts of control switch 145, since the electrode contacts 121 are normally biased to their closed position, alternating current initially pulses through the series combination of coil 63 and the stationary and movable electrodes 13 and 15. This energizes the coil 63 and the salient poles 17a and 17b of rotor 17 tend to line up with the salient poles 94 of the stationary electromagnetic structure. Each of the salient poles of the rotor 17 is initially angularly spaced from its adjacent pole in casing 19 by approximately 60. Each of the rotor poles rotates approximately 60 when the coil is energized to meet one of the stationary poles 94. This causes the electrode contacts to separate by rotation of contact button 127 of movable electrode 15 through an arc of approximately 60". During the separation of these contacts, an ignition arc is produced. Since coil 63 is in series with the electrode contacts, when the contacts open, the coil 63 is deenergized. Spring 129 then acts upon the movable electrode 15 and rotates the movable electrode contact back into engagement with the mating contact of the fixed electrode. As long as current flows in the igniter circuit, movable electrode 15 will thus rotatably oscillate through an angle of approximately 60, producing an arc each time. The structure of the electrodes 13 and 15 has been found to have an important influence on the angular rotation thereof. In particular, upon closure of the contact section 113 of the movable electrode 15 with the contact section 111 of the fixed electrode 13, there is a resilient coaction between these contact sections due to the manner in which they are mounted and the structure of the electrodes. This resilient coaction causes a bouncing effect. The bouncing efiect provided by the resilient coaction of the electrodes 13 and 15 together with the intermittent driving of rotor 17 and rotative spring biasing of movable electrode 15 provides an effective rotation of approximately 60 between the closed and open positions of the movable 6E6- trode.

By placing coil 63 in series with thespring biased electrodes 13 and 15, an efficient cyclic interruption of the electrode contacts is thereby obtained, producing the desired sparking effect. The configuration and structure of the electrodes 13 and 15 is such as to provide a good 5 wiping contact action upon the closure of the contacts. It has been found that the intermittent opening of the electrodes 13 and 15 achieves positive ignition of a combustible gaseous substance at a frequency which enhances the longevity of the device, the device operating in a relatively quiet fashion.

It will now therefore be seen that I have provided a simplified and efficient means for electromagnetically igniting a combustible substance.

While in accordance with the patent statutes, 1 have described what at present is considered to be the preferred embodiment of my invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and I, therefore, aim in the following claims to cover all such equivalent variations as fall within the true spirit and scope of the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An electric ignition device comprising a field structure including a winding, a driving member excited by said field structure, a pair of relatively movable electrodes connected in series with said winding, one of said electrodes being movable about an axis of rotation between two angularly spaced apart positions, means .for energizing the series connection of said winding and said electrodes, means for biasing said one electrode to one of said positions, and means including said driving member for driving the movable electrode to the other of the two positions, said biasing means and said driving means acting alternately upon said movable electrode to effect a rotatably oscillating movement thereof and thereby to provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

2. Anelectric ignition device comprising a field structure including a winding, a rotor excited by said field structure, a pair of electrodes one of which is movable relative to the other connected in series with said winding, said one electrode being movable about an axis of rotation between two angularly spaced apart positions, means for biasing said movable electrode to one of said positions, means for energizing the series connection of said winding and said electrodes, and means including said rotor for driving the movable electrode to the other of the two positions, said biasing means and said driving means being arranged to act alternately upon said movable electrode to effect a rotatable oscillating movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

3. An electric ignition device comprising a stationary field structure including a winding, a rotor excited by said field structure, a pair of electrodes connected in series with said winding, one of said electrodes being movable relative to the other electrode about an axis of rotation between two angularly spaced apart positions, the movable electrode being attached to said rotor and movable therewith, spring biasing means normally urging said movable electrode to a closed one of said positions, means for energizing said electrodes and said winding to excite said rotor and drive said movable electrode from the normally closed position to an open one of said positions, said movable electrode being operated from the open position to the closed position by the spring biasing means, said spring biasing means and said rotor acting alternately upon said movable electrode to effect a rotatable oscillating movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

4. An electric ignition device comprising a stationary field structure including a winding, a rotor excited by said field structure, a pair of electrodes connected in series with said winding, one of said electrodes including an elongated stem section with a contact section fastened to one of its ends and the other end coaxially arranged upon and fastened to said rotor, means for rotatably supporting said stem section thereby to provide a rotatable support for the rotor and the one electrode, spring biasing means normally urging said rotatable one electrode about an axis of rotation of said rotor into engagement with the other electrode, means for electrically energizing the electrodes and winding to excite the rotor and drive the rotatable electrode about said axis of rotation out of engagement with the other electrode, said rotatable electrode being operated from the open position to a closed position by the spring biasing means, said spring biasing means and said rotor acting alternately upon said rotatable electrode to eflect a rotatable oscillating movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

5. An electric ignition device comprising a stationary field structure including a winding, a rotor excited by said structure, a pair of electrodes connected in series with said winding, one of said electrodes movable relative to the other and including an elongated cylindrically configured stem section, said stern section being coaxially arranged upon said rotor with one of its ends fastened to said rotor, the other end of said stem section having a contact strip fastened thereto, said contact strip extending angularly outwardly from the axis of the stem section in a direction generally away from the stem section, means for rotatably supporting said stem section of the movable electrode thereby to provide a rotatable support for the rotor and the movable electrode, spring biasing means acting upon the movable electrode to normally rotatively urge the contact strip of the movable electrode toward a cooperating contact means carried by the other electrode, means for electrically energizing the series connection of said electrodes and said winding and operating the rotor to drive the movable contact strip of the rotatable electrode out of engagement with the contact means of the other electrode, said movable contact strip being operated from the open position to a closed position by the spring biasing means, said spring biasing means and said rotor acting alternately upon said rotatable electrode to effect a rotatable oscillatory movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

6. An electric ignition device comprising a stationary field structure including a winding, a rotor excited by said field structure, a pair of electrodes connected in series with said field structure, one of said electrodes movable relative to the other and including an elongated cylindrically configured stem section, said stem section being coaxially arranged upon said rotor with one of its ends fastened to said rotor, the other of said electrodes having a cylindrical support section the axis of which is parallel to the axis of the stem section of the movable electrode, the other end of the stem section of the movable electrode and an adjacent free end of the support section of the other electrode each having a contact strip fastened thereto, said contact strips extending angularly outwardly from the axes of the stern section and support section respectively in a direction generally away from the stern section and the support section, means for rotatably supporting the stem section of the movable electrode thereby to provide a rotatable support for the rotor and the movable electrode, spring biasing means acting upon the movable electrode to normally rotatively urge the contact strip of the movable electrode toward the contact strip carried by the other electrode, means for electrically energizing the series connection of the electrodes and said winding and exciting the rotor to drive the movable contact strip of the rotatable electrode out of engagement with the contact strip of the other electrode, said movable contact strip being operated from the open position to a closed position by the spring biasing means, said spring biasing means and said rotor acting alternately upon said rotatable electrode to effect a rotatable oscillatory movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

7. An electric ignition device comprising a stationary field structure including a winding, a rotor excited by said field structure, a pair of electrodes connected in series with said winding, one of said electrodes including an elongated stem section with a contact section fastened to one of its ends and the other end coaxially arranged upon and fastened to said rotor, means for rotatably supporting said stem section thereby to provide a rotatable support for the rotor and the one electrode, a first spring normally urging said rotatable electrode into rotative engagement with the other electrode, a second spring acting upon the end of the stem section remote from the contact section to bias said rotatable electrode axially toward its normal position, means for electrically energizing the series connection of said electrodes and said winding and exciting the rotor to drive the rotatable electrode out of engagement with the other electrode, said rotatable electrode being operated from the open position to a closed position by the spring biasing means, said spring biasing means and said excited rotor acting alternately upon said rotatable electrode to efiect a rotatable oscillating movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

8. An electric ignition device comprising a stationary field structure including a winding, a rotor excited by said field structure, a pair of electrodes connected in series with said winding, one of said electrodes including an elongated stem section with a contact section fastened to one of its ends and the other end coaxially arranged upon and fastened to said rotor, a tungsten contact face formed on said contact section for cooperation with a tungsten contact face on the other electrode, means for rotatably supporting said stem section thereby to provide a rotatable support for the rotor and the one electrode, a first spring normally urging said rotatable electrode into rotative engagement with the other electrode, a second spring acting upon the end of the stem section remote from the contact section to bias said rotatable electrode axially toward its normal position, an alternating current source for electrically energizing the series connection of said electrodes and said winding and exciting the rotor to drive the to tatable electrode out of engagement with the other electrode, said rotatable electrode being operated from the open position to a closed position by the spring biasing means, said spring biasing means and said excited rotor acting alternately upon said rotatable electrode to effect a rotatable oscillating movement thereof and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

9. An electric ignition device comprising a stationary field structure; said field structure including a coil, a core extending through said coil, and a generally cylindrical casing surrounding said coil; said coil, core, and casing being in co-axial relationship; a first end of said core dis posed in contiguity with said casing near an associated first end of said casing; the second end of said core disposed in transversely spaced relationship to an associated second end of the casing; salient poles formed in the second end of said casing; a rotor positioned between the second end of the core and the second end of the casing; said ro-tor having salient poles which tend to align themselves with the salient poles of said casing upon energ'ization of said winding; 2 pair of electrodes connected in series withsaid winding, said elecrodes extending outwardly from the first end of the casing and having contact means at the free ends thereof; one of said elecrodes including an elongated stern section with a supported end coaxially arranged upon and fastened to said rotor, means for rotatably supporting said stem section thereby to provide a rotatable support for the rotor and the one electrode, spring biasing means normally urging said rotatable one electrode into engagement with the other electrode, means for electrically energizing the series connection of the electrodes and said stationary field structure and exciting the rotor to drive the rotatable electrode out of engagement with the other electrode, said rotatable electrode being operated from the open position to a closed position by the spring biasing means, said spring biasing means and said rotor acting alternately upon said rotatable electrode to effect a rotatable oscillating movement and thereby provide an intermittent arc voltage drop across the electrodes for ignition of a combustible substance disposed in proximity to the electrodes.

References Cited in the file of this patent UNITED STATES PATENTS Bogart June 6, Tag et al. Sept. 11, Heft June 22, Righetto June 10, Schaifier-Glossl Sept. 25, Russell J an. 2, Rodelli May 2, Weber Feb. 13,

FOREIGN PATENTS Switzerland Feb. 17, Great Britain Feb. 17, France Jan. 10, 

1. AN ELECTRIC IGNITION DEVICE COMPRISING A FIELD STRUCTURE INCLUDING A WINDING, A DRIVING MEMBER EXCITED BY SAID FIELD STRUCTURE, A PAIR OF RELATIVELY MOVABLE ELECTRODES CONNECTED IN SERIES WITH SAID WINDING, ONE OF SAID ELECTRODES BEING MOVABLE ABOUT AN AXIS OF ROTATION BETWEEN TWO ANGULARLY SPACED APART POSITIONS, MEANS FOR ENERGIZING THE SERIES CONNECTION OF SAID WINDING AND SAID ELECTRODES, MEANS FOR BIASING SAID ONE ELECTRODE TO ONE OF SAID POSITIONS, AND MEANS INCLUDING SAID DRIVING MEMBER FOR DRIVING THE MOVABLE ELECTRODE TO THE OTHER OF THE TWO POSITIONS, SAID BIASING MEANS AND SAID DRIVING MEANS ACTING ALTERNATELY UPON SAID MOVABLE ELECTRODE TO EFFECT A 